Close-up on Science

Physicists at the Peter Grünberg Institute have discovered a new magnetic state with the help of computer simulations. It occurs when a magnetic impurity atom is deposited on the surface of a metal. As the electrons of the metal interact with the magnetic field of the impurity atom, ring-shaped waves made up of electrons develop on the surface of the metal. They resemble the waves which form on the surface of a body of water when a stone is dropped into it.